1*bbd72a8cSkettenis /* $OpenBSD: usertc.c,v 1.3 2023/02/05 13:37:51 kettenis Exp $ */
2d82e6535Spirofti /*
3c4e156ddSkettenis * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
4d82e6535Spirofti *
5d82e6535Spirofti * Permission to use, copy, modify, and distribute this software for any
6d82e6535Spirofti * purpose with or without fee is hereby granted, provided that the above
7d82e6535Spirofti * copyright notice and this permission notice appear in all copies.
8d82e6535Spirofti *
9d82e6535Spirofti * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10d82e6535Spirofti * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11d82e6535Spirofti * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12d82e6535Spirofti * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13d82e6535Spirofti * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14d82e6535Spirofti * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15d82e6535Spirofti * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16d82e6535Spirofti */
17d82e6535Spirofti
18d82e6535Spirofti #include <sys/types.h>
19d82e6535Spirofti #include <sys/timetc.h>
20d82e6535Spirofti
21*bbd72a8cSkettenis static inline uint64_t
agtimer_readcnt64_sun50i(void)22*bbd72a8cSkettenis agtimer_readcnt64_sun50i(void)
23*bbd72a8cSkettenis {
24*bbd72a8cSkettenis uint64_t val;
25*bbd72a8cSkettenis int retry;
26*bbd72a8cSkettenis
27*bbd72a8cSkettenis __asm volatile("isb" ::: "memory");
28*bbd72a8cSkettenis for (retry = 0; retry < 150; retry++) {
29*bbd72a8cSkettenis __asm volatile("mrs %x0, CNTVCT_EL0" : "=r" (val));
30*bbd72a8cSkettenis
31*bbd72a8cSkettenis if (((val + 1) & 0x1ff) > 1)
32*bbd72a8cSkettenis break;
33*bbd72a8cSkettenis }
34*bbd72a8cSkettenis
35*bbd72a8cSkettenis return val;
36*bbd72a8cSkettenis }
37*bbd72a8cSkettenis
38c4e156ddSkettenis static inline u_int
agtimer_get_timecount_default(struct timecounter * tc)39*bbd72a8cSkettenis agtimer_get_timecount_default(struct timecounter *tc)
40c4e156ddSkettenis {
41c4e156ddSkettenis uint64_t val;
42c4e156ddSkettenis
43c4e156ddSkettenis /*
44c4e156ddSkettenis * No need to work around Cortex-A73 errata 858921 since we
45c4e156ddSkettenis * only look at the low 32 bits here.
46c4e156ddSkettenis */
47c4e156ddSkettenis __asm volatile("isb" ::: "memory");
48c4e156ddSkettenis __asm volatile("mrs %x0, CNTVCT_EL0" : "=r" (val));
49c4e156ddSkettenis return (val & 0xffffffff);
50c4e156ddSkettenis }
51c4e156ddSkettenis
52*bbd72a8cSkettenis static inline u_int
agtimer_get_timecount_sun50i(struct timecounter * tc)53*bbd72a8cSkettenis agtimer_get_timecount_sun50i(struct timecounter *tc)
54*bbd72a8cSkettenis {
55*bbd72a8cSkettenis return agtimer_readcnt64_sun50i();
56*bbd72a8cSkettenis }
57*bbd72a8cSkettenis
58c4e156ddSkettenis static int
tc_get_timecount(struct timekeep * tk,u_int * tc)59c4e156ddSkettenis tc_get_timecount(struct timekeep *tk, u_int *tc)
60c4e156ddSkettenis {
61c4e156ddSkettenis switch (tk->tk_user) {
62c4e156ddSkettenis case TC_AGTIMER:
63*bbd72a8cSkettenis *tc = agtimer_get_timecount_default(NULL);
64*bbd72a8cSkettenis return 0;
65*bbd72a8cSkettenis case TC_AGTIMER_SUN50I:
66*bbd72a8cSkettenis *tc = agtimer_get_timecount_sun50i(NULL);
67c4e156ddSkettenis return 0;
68c4e156ddSkettenis }
69c4e156ddSkettenis
70c4e156ddSkettenis return -1;
71c4e156ddSkettenis }
72c4e156ddSkettenis
73c4e156ddSkettenis int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount;
74